COCONUT RHINOCEROS BEETLE (CRB)
The coconut rhinoceros beetle (CRB), Oryctes rhinoceros, was first detected on O'ahu in December of 2013. Native to Southeast Asia, adult CRB feed on emerging palm fronds, causing damage that can often be severe enough to kill the plant.
CRB populations can have devastating impacts on palm species that are foundational to cultural heritage, agriculture, ecosystems, and economies, when out of their native range.
Adult coconut rhinoceros beetle (CRB) are black beetles averaging 2 inches in length with a visible horn. They are night-active and can fly. Although they do not bite, they may carry diseases, so they should not be handled with bare hands if possible.
CRB larvae can grow up to three inches before pupating. These larvae crawl on their side and curl into a "C" shape when handled. As larvae, they live and feed on decomposing plant material. CRB prefer coconut palm green waste but can survive in most decaying plant material.
Coconut rhinoceros beetle life stages observed at 30 degrees Celsius. CRB breeding sites are typically established in decaying plant material like mulch, compost, decomposing stumps, or felled trees. After hatching from eggs, larvae begin feeding on the decomposing material. After growing through three larval stages, called instars, larvae pupate and emerge as an adult, leaving the breeding site. CRB spend roughly 5.5 months growing from an egg to an adult, and about 3 - 5 months as an adult.
There are a few look-alike species that are similar to the coconut rhinoceros beetle. This graphic shows some of the key differences in characteristics of the Oriental Flower Beetle (OFB). OFB is a common wide-spread pest that feed on overripe fruit, flower nectar, pollen as well as sap from a variety of plants but their feeding doesn't appear to harm fruiting or flowering productivity.
Dung Beetles and Oriental Flower Beetles are a lot smaller than Coconut Rhinoceros Beetles. CRB will always be about 2 inches long. If it's a smaller beetle, it's most likely one of the look-alike species.
May 2023 - October 2023
Coconut rhinoceros beetle detections have increased in the last 6 months. High-catch areas continue to be Pearl City Peninsula, Waipiʻo Peninsula, West Loch, ʻEwa Beach, Central Oʻahu and West Side of Oʻahu. We are also seeing increased detection on the North Shore as well as concerning trap finds in new areas of Laie, Kahuku and Waimānalo as well as new detections on Kauaʻi. The CRB Response is providing tools for community members to minimize their risk and training businesses to become compliance with HDOA's interim rule.
Although native to Southeast Asia, the distribution of CRB today includes many Pacific Islands, including O'ahu and recently Kauai. To date, CRB has not been reported on any other Hawaiian islands, the mainland United States, Central America, or South America, but any tropical ecosystem that produces host species for the CRB is at risk of infestation.
CRB was discovered at Mamala Bay, O'ahu December 2013. It is assumed the beetle was accidentally introduced on a flight from an infested island in the Pacific. While it was first detected at the airport (HNL), there are both military and commercial flights from areas with CRB populations.
CRB feed on and damage coconut, royal, date, and fan palms. If these preferred food sources are unavailable, CRB can host shift to feed on other palms and tropical crops. CRB use their front legs and horn to dig into the crown of trees. Then, they use their sucking mouthparts to feed on the juices in the inner spear.